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6. Brane intersections, anti-de Sitter spacetimes and dual superconformal theories

Author

Boonstra, Harm Jan, Peeters, Bas, and Skenderis, Kostas

Subjects
High Energy Physics - Theory
Abstract

We construct a class of intersecting brane solutions with horizon geometries of the form adS_k x S^l x S^m x E^n. We describe how all these solutions are connected through the addition of a wave and/or monopoles. All solutions exhibit supersymmetry enhancement near the horizon. Furthermore we argue that string theory on these spaces is dual to specific superconformal field theories in two dimensions whose symmetry algebra in all cases contains the large N=4 algebra A_{gamma}. Implications for gauged supergravities are also discussed., Comment: Latex, 32 pages; references added and minor additions

Published
1998

7. Branes and anti-de Sitter spacetimes

Author

Boonstra, Harm Jan, Peeters, Bas, and Skenderis, Kostas

Subjects
High Energy Physics - Theory
Abstract

We consider a series of duality transformations that leads to a constant shift in the harmonic functions appearing in the description of a configuration of branes. This way, for several intersections of branes, we can relate the original brane configuration which is asymptotically flat to a geometry which is locally isometric to adS_k x E^l x S^m. These results imply that certain branes are dual to supersingleton field theories. We also discuss the implications of our results for supersymmetry enhancement and for supergravity theories in diverse dimensions., Comment: 6 pages, uses neuchatel.sty (included), contribution to proceedings of "Quantum Aspects of Gauge Theories, Supersymmetry and Unification", Neuchatel, September 18-23, 1997

Published
1998
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8. Modelling time change in survey response rates: A Bayesian approach with an application to the Dutch Health Survey

Author

Wu, Shiya, Boonstra, Harm-Jan, Moerbeek, Mirjam, Schouten, Barry, Wu, Shiya, Boonstra, Harm-Jan, Moerbeek, Mirjam, and Schouten, Barry

Abstract

Precise and unbiased estimates of response propensities (RPs) play a decisive role in the monitoring, analysis, and adaptation of data collection. In a fixed survey climate, those parameters are stable and their estimates ultimately converge when sufficient historic data is collected. In survey practice, however, response rates gradually vary in time. Understanding time-dependent variation in predicting response rates is key when adapting survey design. This paper illuminates time-dependent variation in response rates through multi-level time-series models. Reliable predictions can be generated by learning from historic time series and updating with new data in a Bayesian framework. As an illustrative case study, we focus on Web response rates in the Dutch Health Survey from 2014 to 2019.

Published
2023

10. A Markov Chain Monte Carlo approach for the estimation of photovoltaic system parameters

Author

Integration of Photovoltaic Solar Energy, Energy and Resources, Laevens, Benjamin P.M., Pijpers, Frank P., Boonstra, Harm Jan, van Sark, Wilfried G.J.H.M., ten Bosch, Olav, Integration of Photovoltaic Solar Energy, Energy and Resources, Laevens, Benjamin P.M., Pijpers, Frank P., Boonstra, Harm Jan, van Sark, Wilfried G.J.H.M., and ten Bosch, Olav

Published
2023

14. Estimation of level and change for unemployment using structural time series models

Author

Boonstra, Harm Jan, van den Brakel, Jan A., QE Econometrics, and RS: GSBE Theme Data-Driven Decision-Making

Subjects
Small area estimation, Unemployment estimation, Time series multilevel models, PREDICTION, COMPONENTS, STATE-SPACE MODELS, DISTRIBUTIONS, SMALL-AREA ESTIMATION, Structural time series models, ROTATION GROUP BIAS
Abstract

Monthly estimates of provincial unemployment based on the Dutch Labour Force Survey (LFS) are obtained using time series models. The models account for rotation group bias and serial correlation due to the rotating panel design of the LFS. This paper compares two approaches of estimating structural time series models (STM). In the first approach STMs are expressed as state space models, fitted using a Kalman filter and smoother in a frequentist framework. As an alternative, these STMs are expressed as time series multilevel models in an hierarchical Bayesian framework, and estimated using a Gibbs sampler. Monthly unemployment estimates and standard errors based on these models are compared for the twelve provinces of the Netherlands. Pros and cons of the multilevel approach and state space approach are discussed.Multivariate STMs are appropriate to borrow strength over time and space. Modeling the full correlation matrix between time series components rapidly increases the numbers of hyperparameters to be estimated. Modeling common factors is one possibility to obtain more parsimonious models that still account for cross-sectional correlation. In this paper an even more parsimonious approach is proposed, where domains share one overall trend, and have their own independent trends for the domain-specific deviations from this overall trend. The time series modeling approach is particularly appropriate to estimate month-to-month change of unemployment.

Published
2019

16. Internationale handel en doorvoer:een nieuwe statistiek

Author

Lankhuizen, M.B.M., de Blois, Chris, and Boonstra, Harm Jan

Subjects
transit, SDG 17 - Partnerships for the Goals, international trade in goods, international trade in goods, transport, transit, macro-integration, Bayesian model, uncertainty, Bayesian model, transport, macro-integration, uncertainty
Abstract

From way back, the Netherlands is a trading nation. International trade and transport are important sources of income. However, the international transport flows also lead to costs for society. Therefore, careful assessments are needed when investing in infrastructure, transport and logistics. To make such assessments, the availability of quantitative information on international trade and transport flows is essential.The information on international commodity flows is distributed among several statistical products by Statistics Netherlands (CBS): the statistics of international trade in goods and the six transport statistics. Even together these statistics cannot complete the picture of international commodity flows of the Netherlands. Transit is not visible in the statistics. Furthermore, a complete view of the value and weight of commodity flows broken down by content, origin, destination and transport mode is lacking.Now, a new statistics integrates the statistics of international trade and transport by using a Bayesian integration model. The model takes care that the trade and transport figures are mutually consistent and satisfy logical restrictions. This results in a better view of the international commodity flows to, from and through the Netherlands broken down by commodity type and continent of origin or destination. For the first time since 1997, a reliable estimate of transit is available again. Furthermore, the margins around the estimates are determined, which gives insight in the reliability of the figures.

Published
2014

17. Internationale handel en doorvoer: een nieuwe statistiek

Author

Lankhuizen, M.B.M., de Blois, Chris, Boonstra, Harm Jan, and Spatial Economics

Subjects
SDG 17 - Partnerships for the Goals, international trade in goods, transport, transit, macro-integration, Bayesian model, uncertainty
Abstract

From way back, the Netherlands is a trading nation. International trade and transport are important sources of income. However, the international transport flows also lead to costs for society. Therefore, careful assessments are needed when investing in infrastructure, transport and logistics. To make such assessments, the availability of quantitative information on international trade and transport flows is essential. The information on international commodity flows is distributed among several statistical products by Statistics Netherlands (CBS): the statistics of international trade in goods and the six transport statistics. Even together these statistics cannot complete the picture of international commodity flows of the Netherlands. Transit is not visible in the statistics. Furthermore, a complete view of the value and weight of commodity flows broken down by content, origin, destination and transport mode is lacking. Now, a new statistics integrates the statistics of international trade and transport by using a Bayesian integration model. The model takes care that the trade and transport figures are mutually consistent and satisfy logical restrictions. This results in a better view of the international commodity flows to, from and through the Netherlands broken down by commodity type and continent of origin or destination. For the first time since 1997, a reliable estimate of transit is available again. Furthermore, the margins around the estimates are determined, which gives insight in the reliability of the figures.

Published
2014

18. Symmetries in string theory

Author

Boonstra, Harm Jan Hugo, Boonstra, Harm Jan Hugo, Boonstra, Harm Jan Hugo, and Boonstra, Harm Jan Hugo

Abstract

The physics of elementary particles is currently described in terms of a very successful theory called the standard model. It describes all known elementary particles and their interactions except gravitational interactions. The standard model accommodates the quarks and the leptons which are the constituents of matter, the vector particles that mediate the strong and electroweak forces, and the Higgs boson which is expected to account for the masses of the particles. So far, the standard model agrees, often to great accuracy, with all experimental findings ... Zie: Chapter 1

Published
1996

22. Small area estimation to quantify discontinuities in repeated sample surveys.

Author

Brakel, Jan A., Buelens, Bart, and Boonstra, Harm‐Jan

Subjects
SMALL area statistics, CRIME victims, SAMPLING errors, PREDICTION models, LEAST squares
Abstract

During redesigns of repeated surveys, the old and new approaches are often conducted in parallel to quantify discontinuities that are initiated by modifications in the survey process. For budget limitations, the sample size allocated to the alternative approach is often considerably smaller compared with the regular survey that is used for official publication. In this paper, small area estimation techniques are considered to improve the accuracy of domain estimates obtained under the alternative approach. Besides auxiliary information that is available from administrations, direct domain estimates available from the regular survey are useful auxiliary variables to construct model-based small area estimators.These methods are applied to a redesign of the Dutch Crime Victimization Survey. [ABSTRACT FROM AUTHOR]

Published
2016
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